A Manual of the Chemistry of the Carbon Compounds

THE CHEMISTRY OF
The apparatus (Fig. 6) consists
of a glass tube one
metre in length, and about
20 mm. vide, closed at one
end and calibrated. This
tube is filled with mercury
nnd stauds in the little cup
(A), ako containing mercury.
A vacuum is thus obtained,
in which the substance (about
a decigram) contained in a
very8mall stoppered tube is
introduced. The Ion tube
is surrounded by another
tube, 30—40 mm. wide,
drawn out at the upper
end, and widening out at
the lower end, which rests
on a large cork provided
with ftn open narrower tube
(C). Through the xipper end
of the wider tube the vapour
of a licjuid having a constant
boiling-point is passed.
As the vapour of the substance
of which the density
is to be determined forms in
vacuo, the boiling-point of
the substance is so much
lowered that the vapoxir densities
of bodies boiling at
150° and even higher may
be determined by means of
steam. For prodxwsing higher
temperatures, amyl alcohol
(boiliug-point 132°), oil of
turpentine (b. p. 160°), or
aniline (h. p. 182°), are used,
the vapour of these substances
escaping, together
with the replaced mercury,
through the tube (C), which
may be connected with a
condenser. When the liquid
used for heating, toils
briskly, the space between
the inner nnd outer tubes
soon reaches a constant tent-